In a statement Phumzile Mlambo-Ngcuka, UN Women's executive director, said they were "thrilled and honoured" to work with the 24-year-old actress, who recently graduated from Brown University in the US.

They went on to say: "The engagement of young people is critical for the advancement of gender equality in the 21st century, and I am convinced that Emma's intellect and passion will enable UN Women's messages to reach the hearts and minds of young people globally."

"The chance to make a real difference is not an opportunity that everyone is given and is one I have no intention of taking lightly. Women’s rights are something so inextricably linked with who I am, so deeply personal and rooted in my life that I can’t imagine an opportunity more exciting," said Watson.

The star, who has championed education for girls in Zambia and Bangladesh in the past, follows in the footsteps of other famous faces including Nicole Kidman, Angelina Jolie, David Beckham and Orlando Bloom who have taken on roles in the UN.